95 



Quantities of Water Applied to Alfalfa and Yields Secured, Montana 

 Experiment Station. 



Mr. Alex. McPherson, Secretary of the Idaho Board of Horticultural 

 Inspection, states that in southern Idaho 24 inches of water applied pro- 

 duced the maximum crop of alfalfa amounting to seven tons of baled hay, 

 while thirty-six inches produced six and one-third tons; besides the field 

 was damaged to some extent by excessive use of water. 



Mr. Don H. Bark, in charge of Irrigation Investigations in Idaho, has 

 carried on during the past two seasons some very interesting experiments 

 on the water requirements of plants and duty of water. The method used 

 was to select fields averaging about 15 acres on typical farms of the state. 

 These fields were divided into three equal parts. On one part the owner 

 used the same manner of irrigation and same quantity of water as had 

 been his usual custom. On the second part a greater amount was used 

 and on the third part, a smaller amount. The water was carefully meas- 

 ured and the yields weighed to determine the amount giving the greatest 

 yield. The results obtained for the different crops, grain, alfalfa, and 

 clover, are given in the Eighth Biennial Report of the State Engineer 

 of Idaho. 



The only experiment for red clover was made on a two year old clover 

 field with very sandy and gravelly soil. Below 2 feet from the surface and 

 extending to a depth of at least 100 feet, the subsoil was of 35 to 40 per 

 cent, sand and 60 to 65 per cent, coarse gravel. The water table was 55 

 feet from the surface. The field was irrigated by flooding, the water being 

 run over the surface distances from 910 feet to as much as 2359 feet. The 

 results obtained were ES follows: 



The greatest yield was obtained with the medium amount of water. But 

 in all three cases the quantities used are very large and include a waste 

 due to the very open character of the soil and to the long distance the 

 water is run. A large proportion of the water is lost by deep percolation, 

 especially at the upper end of the field. The waste could be lessened by 

 running the water shorter distances, preferably less than 500 feet. 



The experiments for alfalfa were made on a variety of soils. A very 

 sandy and gravelly soil, very similar to the above, was irrigated in the 

 same manner, the water being flooded distances from 1979 to 2550 feet. 



